Force Range
Swiss Quality
Every DMA can only measure in a limited stiffness range. Even if you select the best possible sample geometry, sometimes you have a soft or liquid-like sample or a very stiff sample. In these cases you must apply either a very small or a very high force.
The available force range is: 0.001 to 40 N
Depending on the measurement mode, part of the force is used for stretching the sample. This is the case for tension, compression and 3-point-bending. The dynamic force amplitude for these deformation modes is smaller than the static, so called offset force.
The larger the force range the more experimental flexibility you get.
 | In this example the linear range of the sample is measured. The DMA modes can only be used in the linear range of the stress-strain curve. |
 | This measurement starts in the glassy state of the sample when it is very stiff. On heating, the shock cooled material exhibits a glass transition at -115 °C, crystallization at -100 °C and melting at -40 °C. Afterward it is liquid (G’’ > G’). At 120 °C, the phase angle almost reaches the limit of π/2 radians for a Newtonian fluid (very low stiffness). |
